JP2012241891A - Electric actuator and variable speed drive device - Google Patents

Abstract

To provide an electric actuator and a shift drive device that can detect a synchronization timing with high accuracy and can perform a shift operation after the timing.
In the synchronized state, the load torque during synchronization acting on the shift electromagnetic clutch 43 is transmitted as the drive torque (first current value) of the shift electromagnetic clutch 43 when the drive current value is the first current value. Therefore, the shift electromagnetic clutch 43 slips. When the comparison value between the rotation angle of the shift select shaft and the rotation angle calculated from the detection output of the motor rotation speed sensor 90 is equal to or greater than a predetermined threshold value, it is determined that the shift electromagnetic clutch 43 has slipped. . When the occurrence of slip is determined, the first target current value determination unit 310 determines a second current value higher than the first current value as the target value.
[Selection] Figure 5

Description

  The present invention relates to an electric actuator and a speed change drive device including the same.

  2. Description of the Related Art Conventionally, there is known an automatic manual transmission (Automated Manual Transmission) transmission in which manual transmission is automated. As a drive source for this type of transmission, there has been proposed an electric actuator configured to amplify and output the power of an electric motor with a speed reduction mechanism (see, for example, Patent Document 1). In the description of Patent Document 1, an electromagnetic clutch is interposed between the electric motor and the speed reduction mechanism.

JP 2001-99316 A

  By the way, in the gear shifting operation using the electric actuator, the electric actuator is driven to rotate the shift shaft. At this time, by the rotation of the shift shaft using the electric actuator, the shift fork fixed to the fork shaft connected to the shift shaft is moved in one axial direction of the fork shaft, so that the shift fork is moved to the clutch sleeve. And the clutch sleeve is coupled to the gear to be coupled.

  Usually, the speed change mechanism is provided with a synchro mechanism in order to synchronize the engine speed and the wheel-side speed when gears are engaged. When the gear is engaged, the synchronizer key engages with the clutch sleeve and moves in the axial direction along with the axial movement of the shift fork and the clutch sleeve. Then, the synchronizer key is pressed against the gear to be coupled to the synchronizer member (synchronizer ring), and both are brought into frictional contact. The clutch sleeve and the connection target gear can be connected while the clutch sleeve and the connection target gear are synchronized by the frictional contact between the synchronization member and the connection target gear. The axial position of the shift fork (hereinafter also referred to as “synchronized position”) when the synchro member and the gear to be coupled are brought into frictional contact (this state may be referred to as “synchronized state” hereinafter). Pre-stored in the control unit of the electric actuator. In the gearing operation by the electric actuator, when the sync position approaches, the control unit controls the electric actuator to decelerate the axial movement of the shift fork.

  However, even if the processing accuracy and positioning accuracy of the shift fork, fork shaft and shift select shaft are sufficiently high, due to temperature change, aging degradation, and other factors, the synchro position stored in the control unit of the electric actuator, There may be an error between the position where the synchronized state actually starts. In this case, when the control unit of the electric actuator controls the shift fork in the axial direction based on the erroneous sync position, the shift fork starts to decelerate with the sync member being far away from the gear to be connected. Or the sync member may collide with the gear to be connected in a state where the deceleration is insufficient. Therefore, it is required to accurately detect the position and timing at which the synchronized state occurs (the timing at which the synchronized state occurs is sometimes referred to as “synchronized timing” hereinafter).

Therefore, an object of the present invention is to provide an electric actuator that can detect a predetermined timing and thereby perform a shift operation satisfactorily after the timing.
Another object of the present invention is to provide a speed change drive device that can accurately detect the sync timing and can perform a shift operation after the timing.

  The invention according to claim 1 for achieving the above object is an electric actuator for operating the operating member (15), wherein the electric motor (23) and the power of the electric motor are supplied to the operating member. A shift transmission mechanism (24) for transmitting to the operation member while converting to a driving force for performing a shift operation, and a friction type first that can connect and disconnect power transmission from the electric motor to the shift transmission mechanism. 1 electromagnetic clutch (43), drive current value setting means (310) for setting the drive current value of the first electromagnetic clutch, and the drive current value set in the drive current value setting means, the first electromagnetic clutch An electromagnetic clutch driving means (312) for driving the motor, a motor driving unit (302) for driving the electric motor, and a slip for detecting occurrence of slip in the first electromagnetic clutch The drive current value setting means sets the drive current value of the first electromagnetic clutch to a first level before the occurrence of the slip is detected by the slip determination means. The electric actuator (21) sets the drive current value of the first electromagnetic clutch to a second level higher than the first level after the occurrence of the slip is detected by the slip determination means.

In addition, although the alphanumeric characters in parentheses represent corresponding components in the embodiments described later, the scope of the claims is not intended to be limited to the embodiments. The same applies hereinafter.
According to this configuration, the drive current value of the first electromagnetic clutch is set to the first level before the first electromagnetic clutch slips. If an excessive load is input into the electric actuator via the operation member, an excessive load torque acts on the first electromagnetic clutch. When the excessive load torque exceeds the static friction torque of the first electromagnetic clutch when the drive current value is set to the first level, the first electromagnetic clutch slips. Therefore, by detecting this slip, it is possible to detect the timing at which an excessive load is input into the electric actuator.

Then, after detecting the occurrence of slip by the slip determination means, the setting of the drive current value of the first electromagnetic clutch is raised to the second level. As the drive current value increases to the second level, the static friction torque of the first electromagnetic clutch increases.
At this time, if the static friction torque of the first electromagnetic clutch when the drive current value is set to the second level exceeds the excessive load torque acting on the first electromagnetic clutch, the first electromagnetic clutch The slip that occurred in is eliminated. Then, after the slip is eliminated, the static friction torque generated in the first electromagnetic clutch continues to exceed the excessive load torque acting on the first electromagnetic clutch, so that the first electromagnetic clutch does not slip. Therefore, the power of the electric motor can be reliably transmitted to the operation member via the first electromagnetic clutch, and thus a shift operation after a predetermined timing can be performed satisfactorily.

According to a second aspect of the present invention, the select transmission mechanism (25) for transmitting the power of the electric motor to the operation member while converting the power of the electric motor into a driving force for causing the operation member to perform a selection operation; A friction type second electromagnetic clutch (45) capable of connecting / disconnecting power transmission from the electric motor to the select transmission mechanism may be further included.
According to a third aspect of the present invention for achieving the above object, there are provided a plurality of fork shafts (10A, 10B, 10C), and a shift for operating the operated member (201) fixed to each fork shaft. A fork (11), and by moving the shift fork in the axial direction (M1, M2, M3) of the fork shaft, the synchro member (211) is brought into frictional contact with the connection target gear (200), A speed change drive device (3) for connecting the operated member to the gear to be connected and shifting the speed, wherein the speed change drive device includes a shift operation member for moving the fork shaft in the axial direction thereof. A shift drive apparatus comprising: the electric actuator according to claim 1, wherein the shift operating member is operated to move the fork shaft in an axial direction.

According to this configuration, the drive current value of the first electromagnetic clutch is set to the first level when the gear is not engaged in the shift.
In a state where the synchro member and the gear to be coupled are in frictional contact with each other by movement of the shift fork in the axial direction of the fork shaft (synchronized state), an excessive load from the shift fork is generated inside the electric actuator via the operation member. As a result, an excessive load torque acts on the contact-type first electromagnetic clutch. When the load torque acting on the first electromagnetic clutch in this synchronized state exceeds the static friction torque determined by the first level drive current value, the first electromagnetic clutch slips and the slip occurs. Is detected by the slip determination means. Therefore, the synchro timing can be accurately detected based on the detection of the occurrence of the slip by the slip determination means.

Then, after detecting the slip in the first electromagnetic clutch, the setting of the drive current value of the first electromagnetic clutch is raised to the second level. As the drive current value increases to the second level, the static friction torque of the first electromagnetic clutch increases.
At this time, if the static friction torque of the first electromagnetic clutch when the drive current value is set to the second level exceeds the load torque acting on the first electromagnetic clutch in the synchronized state, the first electromagnetic clutch The slip that occurred in the clutch is eliminated. Then, after the slip is eliminated, the static friction torque generated in the first electromagnetic clutch continues to exceed the load torque acting on the first electromagnetic clutch in the synchronized state, and therefore no slip occurs in the first electromagnetic clutch. Therefore, the power of the electric motor can be reliably transmitted to the operation member via the first electromagnetic clutch, and thereby the shift operation after the synchronization timing can be performed satisfactorily.

Further, in this specification, the first level indicates not only a case where the value of the drive current value is a constant current value (for example, the first current value) but also a range within a certain width. It is. The second level is intended to indicate that the drive current value is within a range having a certain width as well as a constant current value (for example, the second current value).
Further, the first level is a range of a value higher than a drive current value required to generate a static friction torque equivalent to a load torque acting when the friction type first electromagnetic clutch is not in a synchronized state, and The first electromagnetic clutch may be in a range of a value lower than a drive current value necessary to generate a static friction torque equivalent to a load torque acting in the synchronized state.

  Further, the second level may be in a range of a value higher than the drive current value necessary for generating the frictional torque equivalent to the load torque acting when the friction type first electromagnetic clutch is not in the synchronized state. Good.

1 is an exploded perspective view of a schematic configuration of a transmission in which a transmission driving device according to an embodiment of the present invention is incorporated. It is sectional drawing which expands and shows the principal part of the transmission mechanism of the transmission shown in FIG. It is sectional drawing which shows the structure of the electric actuator shown in FIG. It is sectional drawing when cut | disconnecting by cut surface line IV-IV of FIG. It is a block diagram which shows the electrical structure of the electric actuator shown in FIG. It is a graph which shows the change of the amount of axial movements of a shift fork in shift operation, the change of the load which acts on a shift select axis, and the change of the rotational speed of an electric motor. It is a graph which shows the change of the electric current value which flows into the 1st electromagnetic coil of the electromagnetic clutch for a shift.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view of a schematic configuration of a transmission 1 in which a transmission driving device 3 according to an embodiment of the present invention is incorporated. FIG. 2 is an enlarged cross-sectional view showing a main part of the speed change mechanism 5.
Referring to FIG. 1 and FIG. 2, the transmission 1 includes a transmission 2 and a transmission driving device 3 that drives the transmission 2 to change speed. The transmission 2 is a known constant mesh type parallel gear transmission, and is mounted on a vehicle such as a passenger car or a truck. The transmission 2 includes a gear housing 7 and a constantly meshing parallel gear transmission mechanism 5 (not shown in FIG. 1; see FIG. 2) housed in the gear housing 7.

The transmission 2 includes a transmission mechanism 5, a transmission operation mechanism 6 for switching a power transmission path of the transmission mechanism 5 between a plurality of power transmission paths, and a gear housing that houses the transmission mechanism 5 and the transmission operation mechanism 6. 7 and is mounted on vehicles such as passenger cars and trucks. The power transmission ratio can be varied by switching the power transmission path in the transmission mechanism 5.
The speed change mechanism 5 includes a plurality of output shafts (connection target gears) 200 (only one is shown in FIG. 2) and a clutch sleeve 201 (operated member) disposed in association with each output shaft 200. . On the inner periphery of the clutch sleeve 201, a clutch sleeve side spline portion 206 is formed.

  An output-side spline portion 203 is formed at the other end portion (left end portion shown in FIG. 2) of the output shaft 200. A cylindrical synchronizer hub 204 is spline-fitted to the outer periphery of the output-side spline portion 203 so as not to rotate and to allow the output shaft 200 to move in the axial directions M1, M2, and M3. A hub-side spline portion 205 is formed on the outer periphery of the synchronizer hub 204. A synchronizer key 213 is disposed on the outer periphery of the synchronizer hub 204. The inner surface of the synchronizer key 213 is engaged with the hub side spline portion 205, and the outer surface of the synchronizer key 213 protrudes radially outward and engages with the clutch sleeve side spline portion 206 of the clutch sleeve 201. 213A is formed.

An output gear (for example, a third gear in FIG. 2) 220 is externally fitted and fixed to the output side spline portion 203 of the output shaft 200 closer to one end side (right side shown in FIG. 2). A clutch shaft 208 is rotatably fitted via a bearing 209 to the other end portion (left end portion shown in FIG. 2) of the output side spline portion 203 in the output shaft 200.
A cone-shaped first cone surface 210 is formed on the outer periphery of the other end portion (left end portion) of the output gear 220 so as to decrease in diameter toward the other end side. A substantially cylindrical first synchronizer ring 211 is fitted on the first cone surface 210 of the output gear 220 with play. The inner peripheral surface of the first synchronizer ring 211 is formed in a cone shape that matches the first cone surface 210.

  On the outer periphery of one end (right end) of the clutch shaft 208, a cone-shaped second cone surface 222 is formed which has a reduced diameter toward the one end. A substantially cylindrical second synchronizer ring 223 is fitted on the second cone surface 222 of the clutch shaft 208 with play. The inner peripheral surface of the second synchronizer ring 223 is formed in a cone shape that matches the second cone surface 222.

  The speed change operation mechanism 6 is housed in a gear housing 7 and has a plurality of fork shafts 10A, 10B, and 10C extending in parallel to each other. The plurality of fork shafts 10A, 10B, and 10C are juxtaposed so as to be positioned on a straight line when viewed from the axial directions M1, M2, and M3. Fork heads 12A, 12B, and 12C that are driven by the speed change drive device 3 are fixed to the middle portions of the fork shafts 10A, 10B, and 10C. These fork heads 12A, 12B, and 12C are aligned in the axial directions M1, M2, and M3. Further, a shift fork 11 for engaging with the clutch sleeve 201 is fixed to each of the fork shafts 10A, 10B, 10C (FIG. 1 shows only the shift fork 11 provided on the fork shaft 10A).

The shift fork 11 can be engaged with the clutch sleeve 201 by moving the shift fork 11 in the axial direction M1, M2, M3, and the clutch sleeve 201 can be driven in the axial direction M1, M2, M3.
The shift drive device 3 is used as a common drive source for causing the shift operation shaft 6 to perform a shift operation or a select operation, and a shift select shaft (operation member) 15 for causing the shift operation shaft 6 to perform a shift operation or a select operation. Actuator 21.

One end 16 a of an internal lever 16 accommodated in the gear housing 7 is fixed to the middle portion of the shift select shaft 15. The internal lever 16 rotates together with the shift select shaft 15 around the center axis 17 of the shift select shaft 15. One end portion of the shift select shaft 15 (upper right portion shown in FIG. 1) protrudes outside the gear housing 7.
When the shift select shaft 15 is moved in the axial direction M4 by the electric actuator 21, the internal lever 16 is moved in the axial direction M4. As the shift select shaft 15 moves in the axial direction M4, the other end 16b of the internal lever 16 is engaged with the intended shift blocks 12A, 12B, and 12C, thereby achieving the select operation.

  On the other hand, when the shift select shaft 15 is rotated around the central axis 17 by the electric actuator 21, the internal lever 16 swings around the central axis 17. As a result, the shift blocks 12A, 12B, 12C engaged with the internal lever 16 move in the axial directions M1, M2, M3 of the fork shafts 10A, 10B, 10C, and the shift blocks 12A, 12B, 12C Along with the movement, the fork shafts 10A, 10B, 10C and the shift fork 11 move to one of the axial directions M1, M2, M3 (for example, the right side shown in FIG. 2). At this time, the shift fork 11 engages with the clutch sleeve 201, and the clutch sleeve 201 engages with the synchronizer key 213. Therefore, the shift fork 11, the clutch sleeve 201, and the synchronizer key 213 are in the axial directions M1, M2, and M3. Move to one side (for example, the right side shown in FIG. 2). Then, the synchronizer key 213 engages with the first synchronizer ring 211 and presses the first synchronizer ring 211 against the first cone surface 210 of the output gear 220. At this time, a frictional force is generated between the first synchronizer ring 211 and the first cone surface 210, whereby the rotation of the output gear 220 approaches the rotation speed of the clutch sleeve 201.

  After the rotations of the output gear 220 and the clutch sleeve 201 are synchronized, the shift fork 11 is moved toward one of the axial directions M1, M2, and M3 (for example, the right side shown in FIG. 2). At this time, the clutch sleeve 201 accompanies the shift fork 11 and is moved to one of the axial directions M1, M2, and M3 to the gear meshing position (two-dot chain line shown in FIG. 2). When the clutch sleeve 201 is positioned at the gear meshing position, the clutch sleeve 201 surrounds the outer periphery of the first synchronizer ring 211 and the outer periphery of the other side (for example, the left side shown in FIG. 2) end of the output gear 220.

In this state, the clutch sleeve-side spline portion 206 is engaged with the output-side spline portion 215 of the output gear 220, and the clutch sleeve 201 and the output gear 220 are connected. In this state, the gear shifting operation for shifting is completed.
By the way, in the case of such shift gearing operation using the electric actuator 21, the electric actuator 21 is driven to synchronize the rotation of the output gear 220 and the rotation of the clutch sleeve 201, and the shift select shaft 15 and the shift gear 15 are shifted. As the fork 11 moves in the axial direction M1, M2, M3, the first synchronizer ring 211 is frictionally pressed against the first cone surface 210 of the output gear 220 (this frictional contact state may be referred to as a “synchronized state” hereinafter). is there.). In order to satisfactorily perform the gear shifting operation of the shift, the timing at which the first synchronizer ring 211 and the first cone surface 210 begin to make frictional contact (this timing may be referred to as “synchronization timing” hereinafter) with high accuracy. It needs to be detected.

  If the synchronization timing detection accuracy is poor, the first synchronizer ring 211 starts decelerating with the first synchronizer ring 211 being far away from the first cone surface 210, or the first synchronizer ring 211 is not sufficiently decelerated. The output gear 220 may collide. In the former case, since the deceleration period is relatively long, a series of operation times for synchronizing the first synchronizer ring 211 and the output gear 220 may be long. In the latter case, not only the first synchronizer ring 211 and the output gear 220 may be damaged, but the electric actuator 21 may be damaged as a result of applying an excessive load to the electric actuator 21. May fall into a failure state.

The electric actuator 21 includes a housing 22. The electric actuator 21 is fixed to the outer surface of the gear housing 7 or a predetermined portion of the vehicle.
FIG. 3 is a cross-sectional view showing the configuration of the electric actuator shown in FIG. 4 is a cross-sectional view taken along the cutting plane line IV-IV in FIG.
The electric actuator 21 includes, for example, an electric motor 23 formed of a brushless motor, and a shift conversion mechanism (shift transmission) for converting the rotational torque (power) of the electric motor 23 into a force for rotating the shift select shaft 15 around the central axis 17. (Mechanism) 24 and the rotational torque (power) of the electric motor 23 are converted into a force that moves the shift select shaft 15 in the axial direction M4 (a direction perpendicular to the paper surface shown in FIG. 3; the left-right direction shown in FIG. 4). And a switching unit 26 including a clutch mechanism for switching the power transmission destination of the electric motor 23 between the shift conversion mechanism 24 and the select conversion mechanism 25. ing. The electric motor 23, the shift conversion mechanism 24, the select conversion mechanism 25, and the switching unit 26 are accommodated in the housing 22.

  The opening (left side shown in FIG. 3) of the housing 22 is closed by a substantially plate-like lid 27. The housing 22 and the lid 27 are each formed using a metal material such as cast iron or aluminum, for example, and the outer periphery of the lid 27 is fitted into the opening of the housing 22. The lid 27 is formed with a circular through hole 29 penetrating the inner surface (right surface shown in FIG. 3) and the outer surface (left surface shown in FIG. 3).

  The housing 22 includes a substantially box-shaped main housing 22 </ b> A that mainly accommodates the region on the distal end side of the shift select shaft 15 and each component of the shift conversion mechanism 24. The main housing 22A includes a first side wall 111 (see FIG. 4), a second side wall 112 (see FIG. 4), and a first shaft holder for supporting the shift select shaft 15 slightly closer to the proximal end than the distal end portion. 113 (see FIG. 4) and a second shaft holder 114 (see FIG. 4) for accommodating and supporting the tip of the shift select shaft 15.

The inner side surface of the first side wall 111 is a first inner wall surface 111A (see FIG. 4) formed of a flat surface.
The inner side surface of the second side wall 112 is a second inner wall surface 112A (see FIG. 4) formed of a flat surface. The second inner wall surface 112A faces the first inner wall surface 111A and is formed in parallel with the first inner wall surface 111A.

  The first shaft holder 113 is formed to bulge outward from the outer wall surface of the first side wall 111 (the surface opposite to the first inner wall surface 111A), and is formed in a columnar shape, for example. The first shaft holder 113 is formed integrally with the first side wall 111. A cylindrical insertion hole 104 is formed in the first shaft holder 113 and the first side wall 111. The cylindrical insertion hole 104 passes through the first shaft holder 113 and the first side wall 111 in the thickness direction thereof (the left-right direction shown in FIG. 4). The shift select shaft 15 is inserted through the insertion hole 104.

A first slide bearing 101 (see FIG. 4) is fitted and fixed to the inner peripheral wall of the insertion hole 104. The first plain bearing 101 surrounds the outer periphery of the middle portion of the shift select shaft 15 inserted through the insertion hole 104 (slightly closer to the base end than the tip portion), and supports the outer periphery of the middle portion of the shift select shaft 15 in sliding contact. To do.
The second shaft holder 114 is formed to bulge outward from the outer wall surface of the second side wall 112 (the surface opposite to the second inner wall surface 112A), and is formed in, for example, a substantially cylindrical shape. The second shaft holder 114 is formed integrally with the second side wall 112. A cylindrical accommodation groove 115 (see FIG. 4) for accommodating the tip end portion (the right end portion shown in FIG. 4) of the shift select shaft 15 is defined by the inner peripheral surface and the bottom surface of the second shaft holder 114. The inner peripheral wall of the accommodation groove 115 is formed in a cylindrical shape having a central axis coaxial with the cylindrical insertion hole 104.

  A second slide bearing 102 (see FIG. 4) is fitted and fixed to the inner peripheral wall of the accommodation groove 115. The second plain bearing 102 surrounds the outer periphery of the front end portion of the shift select shaft 15 housed in the housing groove 115 and slidably supports the outer periphery of the front end portion. The shift select shaft 15 is supported by the first and second sliding bearings 101 and 102 so as to be rotatable around the central axis 17 and movable in the axial direction M4.

An outer portion of the first slide bearing 101 in the insertion hole 104 is formed between the outer periphery of the shift select shaft 15 and the inner peripheral wall of the insertion hole 104 so that dust and dust do not enter the housing 22 (in the main housing 22A). A seal member 103 for sealing the gap is interposed.
In the first shaft holder 113, a lock ball 106 is disposed between the seal member 103 and the first slide bearing 101 in the thickness direction (left-right direction shown in FIG. 4). Specifically, the lock ball 106 is accommodated in a through hole 105 that passes through the inner peripheral wall of the insertion hole 104 and the outer peripheral surface of the first shaft holder 113. The lock ball 106 extends in a direction (orthogonal direction) perpendicular to the central axis of the cylindrical accommodation groove 115 (that is, the central axis 17 of the shift select shaft 15), has a substantially cylindrical shape, and extends in that direction (orthogonal direction). It is provided so that it can move along. The tip of the lock ball 106 has a hemispherical shape and engages with an engagement groove 107 described below.

  A plurality of (for example, three) engaging grooves 107 extending in the circumferential direction are formed on the outer periphery of the shift select shaft 15 at intervals in the axial direction M4. Each engagement groove 107 is set over the entire circumference. When the lock ball 106 moves in the longitudinal direction, the tip portion protrudes from the inner peripheral wall of the insertion hole 104 toward the central axis 17 (downward in FIG. 4), and the tip portion engages with the engagement groove 107. Thus, the shift select shaft 15 is prevented from moving in the axial direction M4. As a result, the shift select shaft 15 is held with a constant force in a state where the shift select shaft 15 is prevented from moving in the axial direction M4.

A rack (described later) in which the male spline portion 121 (see FIG. 4) and the pinion 36 are engaged between a portion where the first slide bearing 101 is slidably contacted with a portion where the second slide bearing 102 is slidably contacted on the outer periphery of the shift select shaft 15. The part 122 (refer FIG. 4) is formed in this order from the 1st slide bearing 101 side.
As shown in FIG. 3, for example, a brushless motor is employed as the electric motor 23. The electric motor 23 is attached such that its main casing is exposed outside the housing 22. The output shaft 40 of the electric motor 23 extends along a predetermined direction (left-right direction shown in FIG. 3) orthogonal to the shift select shaft 15.

The switching unit 26 includes a transmission shaft 41 that is coaxially connected to the output shaft 40 of the electric motor 23, a first rotor 42 that is coaxial with the transmission shaft 41 and that can be rotated together with the transmission shaft 41, and coaxial with the transmission shaft 41. In addition, a second rotor 44 provided so as to be able to rotate together, and a clutch mechanism 39 for switching the connection destination of the transmission shaft 41 between the first rotor 42 and the second rotor 44 are provided.
The transmission shaft 41 is integral with the main shaft portion 46 at a small-diameter main shaft portion 46 provided on the electric motor 23 side and an axial end portion (right end portion shown in FIG. 3) on the first rotor 42 side of the main shaft portion 46. And a large-diameter portion 47 having a larger diameter than the main shaft portion 46.

The first rotor 42 is disposed on the opposite side to the electric motor 23 side with respect to the transmission shaft 41.
The first rotor 42 includes a first armature hub 54 that projects outward in the radial direction from the outer periphery of the axial end (left end shown in FIG. 3) on the electric motor 23 side. The first armature hub 54 is disposed so as to face the surface (the right surface shown in FIG. 3) of the large diameter portion 47 on the side opposite to the electric motor 23 side.

  The second rotor 44 is disposed on the opposite side of the first rotor 42 with respect to the large diameter portion 47 of the transmission shaft 41, that is, on the electric motor 23 side, and surrounds the main shaft portion 46 of the transmission shaft 41. The second rotor 44 includes a second armature hub 55 that projects outward in the radial direction from the outer periphery of the axial end portion (right end portion shown in FIG. 3) opposite to the electric motor 23 side. The second armature hub 55 is disposed to face the surface of the large diameter portion 47 on the electric motor 23 side (the left surface shown in FIG. 3). In other words, the first rotor 42 (the first armature hub 54) and the second rotor 44 (the second armature hub 55) are arranged so as to sandwich the large-diameter portion 47 of the transmission shaft 41.

The clutch mechanism 39 is connected to and disconnected from the first rotor 42, and is connected to and disconnected from the shift electromagnetic clutch (first electromagnetic clutch) 43 that connects / releases the transmission shaft 41 and the first rotor 42, and the second rotor 44. A selection electromagnetic clutch (second electromagnetic clutch) 45 for connecting / releasing the transmission shaft 41 and the second rotor 44 is provided.
The shift electromagnetic clutch 43 includes a first field 48 and a first armature 49. The first armature 49 has a surface on the other side in the axial direction of the large-diameter portion 47 of the transmission shaft 41 (a right surface shown in FIG. 3) and a surface on the side of the electric motor 23 of the first armature hub 54 (a left surface shown in FIG. 3). It arrange | positions at intervals and has comprised the substantially annular plate shape. The first armature 49 is formed using a ferromagnetic material such as iron. The first field 48 incorporates a first electromagnetic coil 50 in the yoke and is fixed to the housing 22.

  The selection electromagnetic clutch 45 includes a second field 51 and a second armature 52. The second armature 52 has a surface on the one side in the axial direction of the large-diameter portion 47 of the transmission shaft 41 (left surface shown in FIG. 3) and a surface opposite to the electric motor 23 of the second armature hub 55 (right surface shown in FIG. 3). Are spaced apart from each other by a minute interval, and has a substantially annular plate shape. The second armature 52 is formed using a ferromagnetic material such as iron. The second field 51 incorporates a second electromagnetic coil 53 in the yoke and is fixed to the housing 22. The first field 48 and the second field 51 are juxtaposed along the axial direction with the large-diameter portion 47, the first armature hub 54, and the second armature hub 55 interposed therebetween.

  When the first electromagnetic coil 50 is energized, the first electromagnetic coil 50 is excited, and an electromagnetic attractive force is generated in the first field 48 including the first electromagnetic coil 50. Then, the first armature 49 is sucked into the first field 48 and deformed toward the first field 48, and the first armature 49 comes into frictional contact with the first armature hub 54. Accordingly, when the first electromagnetic coil 50 is energized, the first electromagnetic coil 50 is connected to the first rotor 42, and the transmission shaft 41 is coupled to the first rotor 42. When the first electromagnetic coil 50 is turned off (current supply is stopped), the first electromagnetic coil 50 is intermittently connected to the first rotor 42, and the transmission shaft 41 is released from the first rotor 42. That is, by switching between energization / disconnection of the first electromagnetic coil 50, the engaged state and the released state of the shift electromagnetic clutch 43 can be switched.

  On the other hand, when the second electromagnetic coil 53 is energized, the second electromagnetic coil 53 is excited, and an electromagnetic attractive force is generated in the second field 51 including the second electromagnetic coil 53. Then, the second armature 52 is sucked into the second field 51 and deformed toward the second field 51, and the second armature 52 comes into frictional contact with the second armature hub 55. Therefore, when the second electromagnetic coil 53 is energized, the second electromagnetic coil 53 is connected to the second rotor 44 and the transmission shaft 41 is connected to the second rotor 44. When the second electromagnetic coil 53 is turned off (current supply is stopped), the second electromagnetic coil 53 is intermittently connected to the second rotor 44, and the transmission shaft 41 is released from the second rotor 44. That is, by switching between energization / disconnection of the second electromagnetic coil 53, it is possible to switch between the engaged state and the released state of the select electromagnetic clutch 45.

  In this embodiment, only one of the shift electromagnetic clutch 43 and the selection electromagnetic clutch 45 is selectively engaged. That is, when the shift electromagnetic clutch 43 is in the engaged state, the select electromagnetic clutch 45 is in the released state, and when the select electromagnetic clutch 45 is in the engaged state, the shift electromagnetic clutch 43 is in the released state.

A small-diameter annular first gear 56 is externally fitted and fixed to the outer periphery of the second rotor 44. The first gear 56 is provided coaxially with the second rotor 44. The first gear 56 is supported by a rolling bearing 57. An outer ring of the rolling bearing 57 is fitted and fixed to the first gear 56. The inner ring of the rolling bearing 57 is externally fitted and fixed to the outer periphery of the main shaft portion 46 of the transmission shaft 41.
The shift conversion mechanism 24 is moved around the central axis 17 of the shift select shaft 15 in accordance with the axial movement of the ball screw mechanism 58 as a speed reducer that converts rotational motion into linear motion and the nut 59 of the ball screw mechanism 58. And an oscillating arm 60.

The ball screw mechanism 58 includes a screw shaft 61 extending coaxially with the first rotor 42 (or coaxial with the transmission shaft 41), and a nut 59 screwed onto the screw shaft 61 via a ball (not shown). The screw shaft 61 has a relationship with the shift select shaft 15 and a misalignment axis having a misalignment angle of 90 °.
The screw shaft 61 is supported by a rolling bearing 64 while being restricted from moving in the axial direction. Specifically, one end portion (left end portion shown in FIG. 3) of the screw shaft 61 is supported by the rolling bearing 64. An inner ring of the rolling bearing 64 is fitted and fixed to one end of the screw shaft 61. Further, the outer ring of the rolling bearing 64 is fitted in a through hole that is fixed to the housing 22 and penetrates the inner and outer surfaces of the bottom wall 65 of the casing of the switching unit 26. Further, a lock nut 66 is engaged with the outer ring of the rolling bearing 64, and movement of the screw shaft 61 in the other axial direction (to the right in FIG. 3) is restricted. A portion of the one end portion of the screw shaft 61 that is closer to the electric motor 23 than the rolling bearing 64 (on the left side in FIG. 3) is inserted into the inner periphery of the first rotor 42 and is coupled to the first rotor 42 so as to be able to rotate together. Has been. The other end portion (right end portion shown in FIG. 3) of the screw shaft 61 is supported by a rolling bearing 67. The outer ring of the rolling bearing 67 is fixed to the housing 22.

  On one side of the nut 59 (front side shown in FIG. 3; left side shown in FIG. 4) and on the other side opposite to the one side (back side shown in FIG. 3. right side shown in FIG. 4) Are cylindrical projection shafts 70 (only one is shown in FIG. 3) extending in a direction along the axial direction M4 of the shift select shaft 15 (a direction orthogonal to the paper surface shown in FIG. 3; the left-right direction shown in FIG. 4). Are also formed in a protruding manner. The pair of protruding shafts 70 are coaxial. The nut 59 is restricted from rotating around the screw shaft 61 by the first engaging portion 72 of the arm 60. Accordingly, the nut 59 moves in the axial direction of the screw shaft 61 along with the rotation of the screw shaft 61.

The arm 60 includes a first engagement portion 72 for engaging the nut 59, a second engagement portion 73 (see FIG. 4) for engaging the shift select shaft 15, and a first engagement portion 72. A linear connecting rod 74 that connects the second engaging portion 73 is provided. The second engaging portion 73 has a substantially cylindrical shape and is fitted on the shift select shaft 15.
The first engagement portion 72 includes a pair of support plate portions 76 that face each other, and a connection plate portion 77 that connects base end sides of the pair of support plate portions 76 (lower end sides shown in FIGS. 3 and 4). It is substantially U-shaped in side view. Each support plate portion 76 is formed with an outer periphery of each protruding shaft 70 and a U-shaped engaging groove 78 that engages while allowing the protruding shaft 70 to rotate. The U-shaped engaging groove 78 is cut out from the distal end side opposite to the base end side. Therefore, the first engaging portion 72 is engaged with the nut 59 so as to be relatively rotatable around the protruding shaft 70 and to be able to move in the axial direction of the screw shaft 61.

Further, the rotation of the nut 59 around the screw shaft 61 is restricted by the first engaging portion 72 of the arm 60 by the engagement of each U-shaped engaging groove 78 and the protruding shaft 70. Accordingly, the nut 59 and the first engaging portion 72 move in the axial direction of the screw shaft 61 as the screw shaft 61 rotates.
The shift select shaft 15 and the second engagement portion 73 are spline-fitted. Specifically, the male spline 121 provided on the outer periphery of the shift select shaft 15 is engaged with the female spline 75 provided on the inner periphery of the second engaging portion 73. In other words, the second engaging portion 73 is connected to the outer periphery of the shift select shaft 15 in a state in which relative rotation with respect to the shift select shaft 15 is impossible and relative movement is allowed. Accordingly, when the screw shaft 61 rotates and the nut 59 moves in the axial direction of the screw shaft 61 with this rotation, the arm 60 swings around the central axis 17 of the shift select shaft 15, and the arm 60 swings. Along with this, the shift select shaft 15 rotates.

  The select conversion mechanism 25 extends in parallel with the first gear 56, the transmission shaft 41, and is provided at a predetermined position near one end portion (left end portion shown in FIG. 3) of the pinion shaft 95 that is rotatably provided. A second gear 81 fixed coaxially and a small-diameter pinion 36 fixed coaxially at a predetermined position near the other end of the pinion shaft 95 (the right end shown in FIG. 3) constitute a reduction gear as a whole. doing. The second gear 81 is formed with a larger diameter than both the first gear 56 and the pinion 36.

  One end of the pinion shaft 95 (left end shown in FIG. 3) is supported by a rolling bearing 96 fixed to the housing 22. The inner ring of the rolling bearing 96 is externally fitted and fixed to one end portion (left end portion shown in FIG. 3) of the pinion shaft 95. Further, the outer ring of the rolling bearing 96 is fixed in a cylindrical recess 97 formed on the inner surface of the lid 27. Further, the other end portion (right end portion shown in FIG. 3) of the pinion shaft 95 is supported by a rolling bearing 84.

In relation to the other end of the pinion shaft 95, a first rotation angle sensor 87 for detecting the rotation angle (rotation position) of the pinion shaft 95 is disposed. From the detection output of the first rotation angle sensor 87, the axial position of the shift select shaft 15 can be obtained. The detection output of the first rotation angle sensor 87 is input to the ECU 88 described below.
A second rotation angle sensor 89 for detecting the rotation angle (rotation position) of the shift select shaft 15 is disposed in the housing 22 in association with the male spline portion 121 of the shift select shaft 15. . The detection output of the second rotation angle sensor 89 is input to the ECU 88 described below.

The electric motor 23 is provided with a motor rotation speed sensor 90 for detecting the rotation angle (rotation position) of the electric motor 23 and the rotation speed of the electric motor 23. For example, a resolver is employed as the motor rotation speed sensor 90. The detection output of the motor rotation speed sensor 90 is input to the ECU 88 described below.
As shown in FIG. 5, the position information of the operation lever 93 for shifting operation of the vehicle is input to an ECU 88 (Electronic Control Unit). Based on the operation of the operation lever 93, shift control for shifting the shift select shaft 15 and select control for selecting the shift select shaft 15 are executed.

  FIG. 5 is a block diagram showing an electrical configuration of the electric actuator 21. The ECU 88 determines the operation content (shift operation or select operation) using a pre-stored control map based on the rotation angle of the shift select shaft 15, the axial direction M4 position, and the shift position of the operation lever 93. A determination unit 301, a motor drive unit 302 that drives the electric motor 23 based on the determined operation content, a shift electromagnetic clutch drive unit 303 that drives the shift electromagnetic clutch 43, and a selection electromagnetic clutch 45. And a selection electromagnetic clutch drive unit 304 for driving.

  The operation content determination unit 301 includes the axial direction M4 position of the shift select shaft 15 detected by the first rotation angle sensor 87, the rotation angle of the shift select shaft 15 detected by the second rotation angle sensor 89, and the operation lever 93. The position information of the shift position is input to the ECU 88. The motor drive unit 302 includes a motor drive circuit (not shown) that drives the electric motor 23 by, for example, PWM (Pulse Width Modulation) control, and a supply current control unit (not shown) that controls the supply current to the electric motor 23. I have.

  The shift electromagnetic clutch drive unit 303 is a first target current value determination unit that determines a target value (drive current value) of a supply current to the first electromagnetic coil 50 based on the operation content determined by the operation content determination unit 301. (Drive current value setting means) 310, a first output current control unit 311 that controls the output current so that the supply current becomes a target value, and a first clutch drive circuit that drives the shift electromagnetic clutch 43 (electromagnetic clutch drive) Means) 312. The current value of the supply current for the first clutch drive circuit 312 is detected by the first detection circuit 313. The current value detected by the first detection circuit 313 is fed back, and the first output current control unit 311 controls the supply current to be a target value.

  The selection electromagnetic clutch drive unit 304 includes a second target current value determination unit 320 that determines a target value of a supply current to the second electromagnetic coil 53 based on the operation content determined by the operation content determination unit 301, and a supply current Is provided with a second output current control unit 321 that controls the output current so that the value becomes a target value, and a second clutch drive circuit 322 that drives the selection electromagnetic clutch 45. The current value of the supply current for the second clutch drive circuit 322 is detected by the second detection circuit 323. The current value detected by the second detection circuit 323 is fed back and controlled by the second output current control unit 321 so that the supply current becomes the target value.

  The ECU 88 further includes a slip determination unit (slip determination means) 330 that determines whether or not the shift electromagnetic clutch 43 has slipped. Whether or not such a slip occurs is determined by the slip determination unit 330 between the rotation angle of the shift select shaft 15 and the rotation angle calculated from the detection output from the motor rotation speed sensor 90 (rotation angle of the electric motor 23). Comparison value (absolute value of the difference. For example, the rotation angle of the shift select shaft 15 calculated from the rotation angle of the electric motor 23, the lead of the screw shaft 61 and the length of the arm 60, and the output value of the second rotation angle sensor 89) (Comparison value with (rotation position)) is compared with a predetermined threshold value. Specifically, the slip determination unit 330 calculates the comparison value based on the detection output of the second rotation angle sensor 89 and the detection output of the motor rotation speed sensor 90, and the comparison value is equal to or greater than the threshold value. Determine the occurrence of slipping.

  FIG. 6 is a graph showing various changes accompanying the shift operation. (A) shows the change in the amount of movement of the shift fork 11 in the axial direction, (b) shows the change in the load acting on the shift select shaft 15, and (c) shows the change in the rotational speed of the electric motor 23. FIG. 7 is a graph showing changes in the drive current value of the shift electromagnetic clutch 43 (target value of the supply current to the first electromagnetic coil 50).

Next, with reference to FIGS. 2 and 5 to 7, for example, the case of shifting gears from the neutral state will be described. In the neutral state in the transmission 2, the shift fork 11 is located at the neutral position (see FIG. 6A).
In the neutral state, the amount of load acting on the shift select shaft 15 is small as shown in FIG. 6B, and the rotational speed of the electric motor 23 is almost zero as shown in FIG. 6C. is there. From this state, the select electromagnetic clutch 45 is released and the shift electromagnetic clutch 43 is engaged. As shown in FIG. 7, the drive current value of the shift electromagnetic clutch 43 is set to the first current value (first level). The first current value is equivalent to a static torque equivalent to a load torque (referred to as “normal load torque” hereinafter) applied to the friction type shift electromagnetic clutch 43 in a normal state (that is, not in a synchronized state). A load torque ("synchronization time") that is higher than the drive current value necessary for generating torque (the torque that can be transmitted with the first current value) and that is applied to the friction type shift electromagnetic clutch 43 in the synchronized state. Is set to a value lower than the drive current value (hereinafter referred to as “reference current value in synchro state”, which is the same hereinafter) necessary to generate a static friction torque equivalent to “the load torque”. . In other words, the static friction torque of the shift electromagnetic clutch 43 when the drive current value is the first current value is larger than the normal load torque and smaller than the synchronous load torque.

  In addition, the electric motor 23 is started to rotate together with the shift electromagnetic clutch 43 being engaged. As a result, the shift conversion mechanism 24 (see FIG. 3) is driven and the shift select shaft 15 is rotated. The rotation speed of the electric motor 23 is maintained constant after increasing to a predetermined rotation speed (see FIG. 6C). Due to the rotation of the shift select shaft 15, the shift fork 11 is moved toward one of the axial directions M1, M2, and M3 (for example, the right side shown in FIG. 2). At this time, the amount of load acting on the shift select shaft 15 is relatively small (see FIG. 6B).

  As the shift fork 11 moves toward one of the axial directions M1, M2, and M3, the first synchronizer ring 211 frictionally contacts the output gear 220, and the first synchronizer ring 211 presses the output gear 220. When the first synchronizer ring 211 and the output gear 220 are in frictional contact, an excessive load from the shift fork 11 is input to the electric actuator 21 via the shift select shaft 15, and as a result, the synchronizer acting on the shift electromagnetic clutch 43. The load torque at the time exceeds the static friction torque of the shift electromagnetic clutch 43 when the drive current value (the current value for energizing the first electromagnetic coil 50) is the first current value. Therefore, the shift electromagnetic clutch 43 slips (see FIGS. 6B, 6C, and 7). When the shift electromagnetic clutch 43 slips, only a part of the driving force of the electric motor 23 is transmitted to the shift conversion mechanism 24. Therefore, the ratio of the rotation angle of the shift select shaft 15 to the rotation speed of the electric motor 23 is It decreases rapidly. During the shift operation, the slip determination unit 330 compares the rotation angle of the shift select shaft 15 obtained from the detection output of the second rotation angle sensor 89 and the rotation angle calculated from the detection output of the motor rotation speed sensor 90. This comparison value is monitored.

  When the comparison value becomes equal to or greater than the threshold at a timing other than the timing for stopping the shift fork 11, the slip determination unit 330 determines that the shift electromagnetic clutch 43 has slipped. (Detection), and thereby synchronization timing can be detected. Therefore, without providing a new configuration for detecting the synchronization timing, the existing configuration (the shift clutch 43, the second rotation angle sensor 89, and the motor rotation speed sensor 90) provided in the electric actuator 21 is used. The synchro timing can be detected.

  When the sync timing is determined by the slip determination unit 330, the fact is notified to the first target current value determination unit 310, and the first target current value determination unit 310 determines the second current value (the first current value higher than the first current value). 2 level) is determined as a target value. That is, as shown in FIG. 7, the setting of the drive current value of the shift electromagnetic clutch 43 (the current value for energizing the first electromagnetic coil 50) is raised from the first current value to the second current value. As shown in FIG. 7, the second current value is set to a value higher than the reference current value in the synchronized state. In other words, the static friction torque (torque that can be transmitted with the second current value) of the shift electromagnetic clutch 43 when the drive current value is the second current value is larger than the load torque during synchronization.

Therefore, the static friction torque of the shift electromagnetic clutch 43 when the drive current value is the second current value exceeds the load torque at the time of synchronization, and the slip generated in the shift electromagnetic clutch 43 is eliminated, and the shift electromagnetic clutch 43 is securely connected again.
After the slip is eliminated, the static friction torque of the shift electromagnetic clutch 43 determined by the second current value continues to exceed the load torque at the time of synchronization, and as a result, the shift electromagnetic clutch 43 does not slip. Therefore, the driving force of the electric motor 23 can be reliably transmitted to the shift select shaft 15 via the shift electromagnetic clutch 43.

  After the synchronization timing is detected, the ECU 88 decreases the control voltage value of the electric motor 23, for example, and makes the rotation speed of the electric motor 23 extremely low. Thereafter, after the synchronization timing is detected, the ECU 88 increases the control voltage value of the electric motor 23 again to increase the rotation speed of the electric motor 23. As a result, the output gear 220 (see FIG. 2) and the clutch sleeve 201 (see FIG. 2) can be connected, thereby achieving gear engagement and completing the shift operation.

As mentioned above, although one Embodiment of this invention was described, this invention can be implemented also with another form.
For example, the occurrence detection means is not limited to one that determines the occurrence of the slip based on a comparison value between the rotation angle of the shift select shaft 15 and the rotation angle calculated from the detection output of the motor rotation speed sensor 90. For example, a comparison value between the rotation angle of the screw shaft 61 and the rotation angle calculated from the detection output of the motor rotation speed sensor 90, or the rotation angle calculated from the swing position of the arm 60 and the detection output of the motor rotation speed sensor 90. The slippage of the shift electric clutch 43 may be detected based on the comparison value.

In addition, the electric actuator 21 is not capable of selectively switching between a shift operation and a select operation, and may perform only a shift operation.
Further, the operating means is not limited to the shift select shaft 15 in which the internal lever 16 is integrated with the shaft, and a shift shaft provided separately from the internal lever 16 may be employed.

Further, in the above-described embodiment, the case where the electric actuator 21 is applied to the speed change drive device 3 has been described as an example. However, the electric actuator 21 can be used as a drive source for various applications.
In addition, various design changes can be made within the scope of matters described in the claims.

DESCRIPTION OF SYMBOLS 3 ... Variable speed drive apparatus, 10A ... Fork shaft, 10B ... Fork shaft, 10C ... Fork shaft, 11 ... Shift fork, 15 ... Shift select shaft (operation member), 21 ... Electric actuator, 23 ... Electric motor, 24 ... Shift conversion Mechanism (shift transmission mechanism), 25 ... select conversion mechanism (select transmission mechanism), 43 ... shift electromagnetic clutch (first electromagnetic clutch), 45 ... select electromagnetic clutch (second electromagnetic clutch), 200 ... output shaft (connection) Target gear), 201 ... clutch sleeve, 211 ... first synchronizer ring, 302 ... motor drive unit, 310 ... first target current value determining unit (drive current value setting means), 312 ... first clutch drive circuit (electromagnetic clutch drive) Means), 330... Synchronization timing determination unit (slip determination means), M1, M2, M3... Axial direction

Claims (3)

An electric actuator for operating the operation member,
An electric motor;
A shift transmission mechanism for transmitting the power of the electric motor to the operation member while converting the driving force to cause the operation member to perform a shift operation;
A friction type first electromagnetic clutch capable of connecting / disconnecting power transmission from the electric motor to the shift transmission mechanism;
Drive current value setting means for setting a drive current value of the first electromagnetic clutch;
An electromagnetic clutch driving means for driving the first electromagnetic clutch at a driving current value set in the driving current value setting means;
A motor driving unit for driving the electric motor;
Slip determination means for detecting occurrence of slip in the first electromagnetic clutch,
The drive current value setting means sets the drive current value of the first electromagnetic clutch to a first level before the occurrence of the slip is detected by the slip determination means, and the slip determination means sets the slip current. An electric actuator configured to set a driving current value of the first electromagnetic clutch to a second level higher than the first level after occurrence is detected. A select transmission mechanism for transmitting the power of the electric motor to the operation member while converting the driving force to cause the operation member to perform a selection operation;
The electric actuator according to claim 1, further comprising a friction-type second electromagnetic clutch capable of connecting / disconnecting power transmission from the electric motor to the select transmission mechanism. A plurality of fork shafts and a shift fork that is fixed to each fork shaft and operates an operated member, and by moving the shift fork in the axial direction of the fork shaft, the synchro member is connected to the gear to be connected. A shift drive device for driving a transmission that connects the operated member to the gear to be connected while being in frictional contact with the gear,
The shift drive device includes a shift operation member for moving the fork shaft in the axial direction thereof, and
A speed change drive apparatus comprising: the electric actuator according to claim 1 or 2, wherein the shift operation member is operated to move the fork shaft in an axial direction.

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